香蕉GLR基因家族全基因组鉴定及其响应低温与脱落酸/茉莉酸甲酯的表达分析

Genome-wide identification of the banana GLR gene family and its expression analysis in response to low temperature and abscisic acid/methyl jasmonate

摘要:

植物类谷氨酸受体（glutamate receptor-like，GLR）是一类重要的Ca²⁺通道蛋白，在植物的生长发育以及响应生物和非生物胁迫等方面有着重要作用。本研究基于香蕉基因组数据，对香蕉GLR基因家族进行全基因组鉴定，分析基本理化性质、基因结构、保守基序、启动子顺式作用元件和进化关系，并采用实时荧光定量聚合酶链式反应（real-time fluorescence quantitative polymerase chain reaction，RT-qPCR）验证GLR家族部分成员在4℃低温和不同激素处理下的表达模式。研究结果表明：香蕉A （Musa acuminata）基因组有19个MaGLR家族成员、B （Musa balbisiana）基因组16个MbGLR家族成员、阿宽蕉（Musa itinerans）基因组有14个MiGLR家族成员；大多数成员为稳定蛋白，绝大多数成员具有信号肽，均有3–6个跨膜结构；亚细胞定位预测均定位于质膜上，在染色体上无规则分布。进化树分析发现，香蕉GLR分为3个亚族。启动子顺式作用元件和转录因子结合位点（transcription factor binding site，TFBS）预测结果显示，香蕉GLR存在多种与激素、胁迫相关响应元件以及18种TFBS。RT-qPCR分析表明，MaGLR1.1、MaGLR3.5在4℃低温胁迫下积极响应且脱落酸、茉莉酸甲酯处理中均有显著表达。本研究结果表明GLR是一种高度保守的离子通道家族，在香蕉生长发育过程和抗逆性方面可能发挥着重要作用。

关键词:香蕉;GLR;家族鉴定;低温;表达分析

Abstract:

Glutamate receptor-like (GLR) is an important class of Ca²⁺ channel proteins, playing important roles in plant growth and development as well as in response to biotic and abiotic stresses. In this paper, we performed genome-wide identification of banana GLR gene family based on banana genomic data. Moreover, we analyzed the basic physicochemical properties, gene structure, conserved motifs, promoter cis-acting elements, evolutionary relationships, and used real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) to verify the expression patterns of some GLR family members under low temperature of 4℃ and different hormone treatments. The results showed that there were 19 MaGLR family members in Musa acuminata, 16 MbGLR family members in Musa balbisiana and 14 MiGLR family members in Musa itinerans. Most of the members were stable proteins and had signal peptides, all of them had 3-6 transmembrane structures. Prediction of subcellular localization indicated that all of them were localized on the plasma membrane and irregularly distributed on the chromosome. Phylogenetic analysis revealed that banana GLRs could be divided into 3 subclades. The results of promoter cis-acting elements and transcription factor binding site prediction showed that there were multiple hormone- and stress-related response elements and 18 TFBS in banana GLR. RT-qPCR analysis showed that MaGLR1.1 and MaGLR3.5 responded positively to low temperature stress and were significantly expressed in abscisic acid/methyl jasmonate treatments. In conclusion, the results of this study suggest that GLR, a highly conserved family of ion channels, may play an important role in the growth and development process and stress resistance of banana.

Key words:banana;GLR;family identification;low temperature;expression analysis